The present invention relates to roof cooling systems for residential, commercial and industrial buildings and particularly to roof cooling systems which reduce the heat load on internal air conditioning equipment. More particularly, the invention relates to evaporative roof cooling to substantially eliminate the radiant or solar roof heat load imposed on buildings, and to reduce inside temperatures in buildings without internal air conditioning.
A number of prior art patents have disclosed exterior roof cooling devices and systems for cooling the interior of buildings. In Barnes U.S. Pat. No. 1,808,829 the inventor proposes that a water absorbent material, such as burlap or canvas, be applied to the roof and side walls from a high point of the building to its base area with the travel of the water through the facing material providing cooling of the interior of the building. Holder in his U.S. Pat. No. 2,266,321 discloses a roof cooling system comprised of: a plurality of spray heads with water supply conduit means; automatic valve means for the conduit means; and control means for the valve means including a heat responsive bulb means enclosed in a ventilated housing mounted on the roof. The expansible fluid within the sealed bulb responds to temperature variation of the bulb to set up varying pressure conditions at the central means for actuating the automatic valve thereby controlling the flow or non-flow of water through the conduit means to the spray heads. The temperature of the heat responsive bulb is related to the atmospheric temperature of the space surrounding the bulb within its ventilated housing. In Gerhart U.S. Pat. No. 2,660,863 the inventor proposes a roof cooling system including the use of a porous hose, such as a canvas tube, to diffuse water slowly near and along the ridge of the roof without producing a spray. The diffusion hose is so arranged as to maintain a trickle of water over the whole roof or an apprpriate portion thereof. Unevaporated water is collected in the roof's gutters and leaders and delivered to a sump for recirculation with make-up water.
It is an object of the present invention to provide an improved roof cooling and heat dissipation system for residential, commercial and industrial buildings to economically lower the under roof temperature of such structures, and thereby reduce the air conditioning loads and costs thereof.
It is a further object of the invention to provide an evaporative roof cooling system, including water conduits with associated mist/spray nozzles, and a programmed water supply control system, including an electronic temperature sensor for accurately monitoring and measuring the temperature of the roof, to cool the roof in part by water mist interception of solar radiation to the roof, and in part by pulling heat from the roof through the evaporation of water sprayed thereon.
Another object of the invention is to provide an evaporative roof cooling system including a control system responsive to the temperature of the roof which directs the cyclic spraying of a mist/spray of water in a uniform pattern over the surface of the roof between a high and low temperature range of roof temperatures.
Yet another object of the invention is to provide an improved method for the controlled cyclic application of a mist/spray of water in a uniform pattern over the surface of a roof exposed to high levels of solar radiation to evaporatively cool the roof between high and low temperature set points of roof temperatures as monitored and measured by an electronic temperature sensor.
These and other objects and advantages of the invention will become more apparent from the following summary and detailed descriptions taken in conjunction with the accompanying drawing figures.